BRMS, incremental saves, last saved date.

Hey all,

does anyone know what BRMS uses to decide whether to save a file on an
incremental backup?

In other words, if I do a BRMS weekly full save, and daily
incrementals, but lets say on wednesday I make a change to a file, and
save that file to another tap drive or a savefile using SAVOBJ (or
even SAVOBJBRM).   Does that file get backed up that night on my
incremental too?  or will it treat the last SAVOBJ as sufficient to
not save the file?

in still other words, does BRMS keep track of it's own last save
date/time or does it use the object's last save date/time?

The problem I'm going to have is that there are several places in the
software where a file or files are saved to savfile, not via BRMS. 
These save files could possibly be overwritten later, and BRMS would
not know about it.

Thanks,

Rick